My parents said the same shit, and I knew others' parents who did too. I dismissed it as an excuse to free up the TV because I couldn't see them really buying me an Atari if they knew it caused TV damage and I never heard of anyone I knew having this problem. Aside from that, I couldn't see a multi-zillion-dollar company selling millions of these units if they knew there was a risk because they'd have lost their asses in lawsuits. I ended up going to the neighbor's house to play it on a big TV and only used mine a few times.
I asked my cat what the meaning of life was... he noserized me and stuck his butt in my face.